/*
   * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code
   *
   * 5/2/94 Roman Hodek:
   *  Added support for TT interrupts; setup for TT SCU (may someone has
   *  twiddled there and we won't get the right interrupts :-()
   *
   *  Major change: The device-independent code in m68k/ints.c didn't know
   *  about non-autovec ints yet. It hardcoded the number of possible ints to
   *  7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the
   *  number of possible ints a constant defined in interrupt.h, which is
   *  47 for the Atari. So we can call request_irq() for all Atari interrupts
   *  just the normal way. Additionally, all vectors >= 48 are initialized to
   *  call trap() instead of inthandler(). This must be changed here, too.
   *
   * 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>:
   *  Corrected a bug in atari_add_isr() which rejected all SCC
   *  interrupt sources if there were no TT MFP!
   *
   * 12/13/95: New interface functions atari_level_triggered_int() and
   *  atari_register_vme_int() as support for level triggered VME interrupts.
   *
   * 02/12/96: (Roman)
   *  Total rewrite of Atari interrupt handling, for new scheme see comments
   *  below.
   *
   * 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>:
   *  Added new function atari_unregister_vme_int(), and
   *  modified atari_register_vme_int() as well as IS_VALID_INTNO()
   *  to work with it.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details.
   *
   */
  
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/kernel_stat.h>
  #include <linux/init.h>
  #include <linux/seq_file.h>
  #include <linux/module.h>
  
  #include <asm/traps.h>
  
  #include <asm/atarihw.h>
  #include <asm/atariints.h>
  #include <asm/atari_stdma.h>
  #include <asm/irq.h>
  #include <asm/entry.h>
  #include <asm/io.h>
  
  
  /*
   * Atari interrupt handling scheme:
   * --------------------------------
   *
   * All interrupt source have an internal number (defined in
   * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
   * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
   * be allocated by atari_register_vme_int().
   */
  
  /*
   * Bitmap for free interrupt vector numbers
   * (new vectors starting from 0x70 can be allocated by
   * atari_register_vme_int())
   */
  static int free_vme_vec_bitmap;
  
  /* GK:
   * HBL IRQ handler for Falcon. Nobody needs it :-)
   * ++andreas: raise ipl to disable further HBLANK interrupts.
   */
  asmlinkage void falcon_hblhandler(void);
  asm(".text
  "
  __ALIGN_STR "
  \t"
  "falcon_hblhandler:
  \t"
  	"orw	#0x200,%sp@
  \t"	/* set saved ipl to 2 */
  	"rte");
  
  extern void atari_microwire_cmd(int cmd);
  
  static unsigned int atari_irq_startup(struct irq_data *data)
  {
  	unsigned int irq = data->irq;
  
  	m68k_irq_startup(data);
  	atari_turnon_irq(irq);
  	atari_enable_irq(irq);
  	return 0;
  }
  
  static void atari_irq_shutdown(struct irq_data *data)
  {
  	unsigned int irq = data->irq;
  
  	atari_disable_irq(irq);
  	atari_turnoff_irq(irq);
  	m68k_irq_shutdown(data);
  
  	if (irq == IRQ_AUTO_4)
  	    vectors[VEC_INT4] = falcon_hblhandler;
  }
  
  static void atari_irq_enable(struct irq_data *data)
  {
  	atari_enable_irq(data->irq);
  }
  
  static void atari_irq_disable(struct irq_data *data)
  {
  	atari_disable_irq(data->irq);
  }
  
  static struct irq_chip atari_irq_chip = {
  	.name		= "atari",
  	.irq_startup	= atari_irq_startup,
  	.irq_shutdown	= atari_irq_shutdown,
  	.irq_enable	= atari_irq_enable,
  	.irq_disable	= atari_irq_disable,
  };
  
  /*
   * ST-MFP timer D chained interrupts - each driver gets its own timer
   * interrupt instance.
   */
  
  struct mfptimerbase {
  	volatile struct MFP *mfp;
  	unsigned char mfp_mask, mfp_data;
  	unsigned short int_mask;
  	int handler_irq, mfptimer_irq, server_irq;
  	char *name;
  } stmfp_base = {
  	.mfp		= &st_mfp,
  	.int_mask	= 0x0,
  	.handler_irq	= IRQ_MFP_TIMD,
  	.mfptimer_irq	= IRQ_MFP_TIMER1,
  	.name		= "MFP Timer D"
  };
  
  static irqreturn_t mfptimer_handler(int irq, void *dev_id)
  {
  	struct mfptimerbase *base = dev_id;
  	int mach_irq;
  	unsigned char ints;
  
  	mach_irq = base->mfptimer_irq;
  	ints = base->int_mask;
  	for (; ints; mach_irq++, ints >>= 1) {
  		if (ints & 1)
  			generic_handle_irq(mach_irq);
  	}
  	return IRQ_HANDLED;
  }
  
  
  static void atari_mfptimer_enable(struct irq_data *data)
  {
  	int mfp_num = data->irq - IRQ_MFP_TIMER1;
  	stmfp_base.int_mask |= 1 << mfp_num;
  	atari_enable_irq(IRQ_MFP_TIMD);
  }
  
  static void atari_mfptimer_disable(struct irq_data *data)
  {
  	int mfp_num = data->irq - IRQ_MFP_TIMER1;
  	stmfp_base.int_mask &= ~(1 << mfp_num);
  	if (!stmfp_base.int_mask)
  		atari_disable_irq(IRQ_MFP_TIMD);
  }
  
  static struct irq_chip atari_mfptimer_chip = {
  	.name		= "timer_d",
  	.irq_enable	= atari_mfptimer_enable,
  	.irq_disable	= atari_mfptimer_disable,
  };
  
  
  /*
   * EtherNAT CPLD interrupt handling
   * CPLD interrupt register is at phys. 0x80000023
   * Need this mapped in at interrupt startup time
   * Possibly need this mapped on demand anyway -
   * EtherNAT USB driver needs to disable IRQ before
   * startup!
   */
  
  static unsigned char *enat_cpld;
  
  static unsigned int atari_ethernat_startup(struct irq_data *data)
  {
  	int enat_num = 140 - data->irq + 1;
  
  	m68k_irq_startup(data);
  	/*
  	* map CPLD interrupt register
  	*/
  	if (!enat_cpld)
  		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
  	/*
  	 * do _not_ enable the USB chip interrupt here - causes interrupt storm
  	 * and triggers dead interrupt watchdog
  	 * Need to reset the USB chip to a sane state in early startup before
  	 * removing this hack
  	 */
  	if (enat_num == 1)
  		*enat_cpld |= 1 << enat_num;
  
  	return 0;
  }
  
  static void atari_ethernat_enable(struct irq_data *data)
  {
  	int enat_num = 140 - data->irq + 1;
  	/*
  	* map CPLD interrupt register
  	*/
  	if (!enat_cpld)
  		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
  	*enat_cpld |= 1 << enat_num;
  }
  
  static void atari_ethernat_disable(struct irq_data *data)
  {
  	int enat_num = 140 - data->irq + 1;
  	/*
  	* map CPLD interrupt register
  	*/
  	if (!enat_cpld)
  		enat_cpld = (unsigned char *)ioremap((ATARI_ETHERNAT_PHYS_ADDR+0x23), 0x2);
  	*enat_cpld &= ~(1 << enat_num);
  }
  
  static void atari_ethernat_shutdown(struct irq_data *data)
  {
  	int enat_num = 140 - data->irq + 1;
  	if (enat_cpld) {
  		*enat_cpld &= ~(1 << enat_num);
  		iounmap(enat_cpld);
  		enat_cpld = NULL;
  	}
  }
  
  static struct irq_chip atari_ethernat_chip = {
  	.name		= "ethernat",
  	.irq_startup	= atari_ethernat_startup,
  	.irq_shutdown	= atari_ethernat_shutdown,
  	.irq_enable	= atari_ethernat_enable,
  	.irq_disable	= atari_ethernat_disable,
  };
  
  /*
   * void atari_init_IRQ (void)
   *
   * Parameters:	None
   *
   * Returns:	Nothing
   *
   * This function should be called during kernel startup to initialize
   * the atari IRQ handling routines.
   */
  
  void __init atari_init_IRQ(void)
  {
  	m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
  	m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
  				  NUM_ATARI_SOURCES - 1);
  
  	/* Initialize the MFP(s) */
  
  #ifdef ATARI_USE_SOFTWARE_EOI
  	st_mfp.vec_adr  = 0x48;	/* Software EOI-Mode */
  #else
  	st_mfp.vec_adr  = 0x40;	/* Automatic EOI-Mode */
  #endif
  	st_mfp.int_en_a = 0x00;	/* turn off MFP-Ints */
  	st_mfp.int_en_b = 0x00;
  	st_mfp.int_mk_a = 0xff;	/* no Masking */
  	st_mfp.int_mk_b = 0xff;
  
  	if (ATARIHW_PRESENT(TT_MFP)) {
  #ifdef ATARI_USE_SOFTWARE_EOI
  		tt_mfp.vec_adr  = 0x58;		/* Software EOI-Mode */
  #else
  		tt_mfp.vec_adr  = 0x50;		/* Automatic EOI-Mode */
  #endif
  		tt_mfp.int_en_a = 0x00;		/* turn off MFP-Ints */
  		tt_mfp.int_en_b = 0x00;
  		tt_mfp.int_mk_a = 0xff;		/* no Masking */
  		tt_mfp.int_mk_b = 0xff;
  	}
  
  	if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
  		atari_scc.cha_a_ctrl = 9;
  		MFPDELAY();
  		atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
  	}
  
  	if (ATARIHW_PRESENT(SCU)) {
  		/* init the SCU if present */
  		tt_scu.sys_mask = 0x10;		/* enable VBL (for the cursor) and
  									 * disable HSYNC interrupts (who
  									 * needs them?)  MFP and SCC are
  									 * enabled in VME mask
  									 */
  		tt_scu.vme_mask = 0x60;		/* enable MFP and SCC ints */
  	} else {
  		/* If no SCU and no Hades, the HSYNC interrupt needs to be
  		 * disabled this way. (Else _inthandler in kernel/sys_call.S
  		 * gets overruns)
  		 */
  
  		vectors[VEC_INT2] = falcon_hblhandler;
  		vectors[VEC_INT4] = falcon_hblhandler;
  	}
  
  	if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
  		/* Initialize the LM1992 Sound Controller to enable
  		   the PSG sound.  This is misplaced here, it should
  		   be in an atasound_init(), that doesn't exist yet. */
  		atari_microwire_cmd(MW_LM1992_PSG_HIGH);
  	}
  
  	stdma_init();
  
  	/* Initialize the PSG: all sounds off, both ports output */
  	sound_ym.rd_data_reg_sel = 7;
  	sound_ym.wd_data = 0xff;
  
  	m68k_setup_irq_controller(&atari_mfptimer_chip, handle_simple_irq,
  				  IRQ_MFP_TIMER1, 8);
  
  	irq_set_status_flags(IRQ_MFP_TIMER1, IRQ_IS_POLLED);
  	irq_set_status_flags(IRQ_MFP_TIMER2, IRQ_IS_POLLED);
  
  	/* prepare timer D data for use as poll interrupt */
  	/* set Timer D data Register - needs to be > 0 */
  	st_mfp.tim_dt_d = 254;	/* < 100 Hz */
  	/* start timer D, div = 1:100 */
  	st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 0xf0) | 0x6;
  
  	/* request timer D dispatch handler */
  	if (request_irq(IRQ_MFP_TIMD, mfptimer_handler, IRQF_SHARED,
  			stmfp_base.name, &stmfp_base))
  		pr_err("Couldn't register %s interrupt
  ", stmfp_base.name);
  
  	/*
  	 * EtherNAT ethernet / USB interrupt handlers
  	 */
  
  	m68k_setup_irq_controller(&atari_ethernat_chip, handle_simple_irq,
  				  139, 2);
  }
  
  
  /*
   * atari_register_vme_int() returns the number of a free interrupt vector for
   * hardware with a programmable int vector (probably a VME board).
   */
  
  unsigned int atari_register_vme_int(void)
  {
  	int i;
  
  	for (i = 0; i < 32; i++)
  		if ((free_vme_vec_bitmap & (1 << i)) == 0)
  			break;
  
  	if (i == 16)
  		return 0;
  
  	free_vme_vec_bitmap |= 1 << i;
  	return VME_SOURCE_BASE + i;
  }
  EXPORT_SYMBOL(atari_register_vme_int);
  
  
  void atari_unregister_vme_int(unsigned int irq)
  {
  	if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
  		irq -= VME_SOURCE_BASE;
  		free_vme_vec_bitmap &= ~(1 << irq);
  	}
  }
  EXPORT_SYMBOL(atari_unregister_vme_int);